Weird issue between data, and voice.

Lately I have been getting very poor signal strength on my Hero. It went from 3 or 4 bars, down to 1 or 2 at my house, and I constantly drop calls. I live in an area where I am supposed to have excellent signal strength too. Called tech support, they checked the towers, and all is fine.
I have my phone set to Sprint only, and whenever I make a call, and end the call, my signal drops to 0, and sometimes even get an x meaning no signal, but either way what bothers me is when I end the call my data, whether it is Ev, or 1x lights up and sends/receive's data for about 5 seconds. After that the signal comes back. Now what in the world does data have to do with voice?? Nothing.
My phone is stock with no 3rd party apps installed at all.
I have reset to factory too, doesn't help Firmware and PRL are both up to date too.
Any ideas?